An aircraft having a systems cabinet positioned in an avionics bay to the rear of a landing gear compartment and connected to the fuselage by at least one lower connecting system. The systems cabinet and/or the lower connecting system comprises at least one longitudinal beam, which has a front end connected by a front connection to a wall separating the avionics bay and the landing gear compartment, the front connection comprising a sliding connection sliding in a direction substantially parallel to the longitudinal axis.